2,181 research outputs found

    Production, Characterisation and Assessment of Biomixture Fuels for Compression Ignition Engine Application

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    Hardly any neat biodiesel satisfies the European EN14214 standard for compression ignition engine application. To satisfy the EN14214 standard, various additives are doped into biodiesel; however, biodiesel additives might cause other problems such as increase in the particular emission and increased specific fuel consumption. In addition, the additives could be expensive. Considering the increasing level of greenhouse gas GHG emissions and fossil fuel depletion, it is forecasted that the use of biodiesel will be higher in the near future. Hence, the negative aspects of the biodiesel additives will likely to gain much more importance and need to be replaced with better solutions. This study aims to satisfy the European standard EN14214 by blending the biodiesels derived from sustainable feedstocks. Waste Cooking Oil (WCO) and Animal Fat Oil (AFO) are two sustainable feedstocks in the EU (including the UK) for producing biodiesels. In the first stage of the study, these oils were transesterified separately and neat biodiesels (W100 & A100) were produced. Secondly, the biodiesels were blended together in various ratios: 80% WCO biodiesel and 20% AFO biodiesel (W80A20), 60% WCO biodiesel and 40% AFO biodiesel (W60A40), 50% WCO biodiesel and 50% AFO biodiesel (W50A50), 30% WCO biodiesel and 70% AFO biodiesel (W30A70), 10% WCO biodiesel and 90% AFO biodiesel (W10A90). The prepared samples were analysed using Thermo Scientific Trace 1300 Gas Chromatograph and ISQ LT Mass Spectrometer (GC-MS). The GSMS analysis gave Fatty Acid Methyl Ester (FAME) breakdowns of the fuel samples. It was found that total saturation degree of the samples was linearly increasing (from 15% for W100 to 54% for A100) as the percentage of the AFO biodiesel was increased. Furthermore, it was found that WCO biodiesel was mainly (82%) composed of polyunsaturated FAMEs. Cetane numbers, iodine numbers, calorific values, lower heating values and the densities (at 15 oC) of the samples were estimated by using the mass percentages data of the FAMEs. Besides, kinematic viscosities (at 40 °C and 20°C), densities (at 15 °C), heating values and flash point temperatures of the biomixture samples were measured in the lab. It was found that estimated and measured characterisation results were comparable. The current study concluded that biomixture fuel samples W60A40 and W50A50 were perfectly satisfying the European EN 14214 norms without any need of additives. Investigation on engine performance, exhaust emission and combustion characteristics will be conducted to assess the full feasibility of the proposed biomixture fuels

    Combustion characteristics of cottonseed biodiesel and chicken fat biodiesel mixture in a multi-cylinder compression ignition engine

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    Although waste animal fats such as chicken fat are promising alternative energy sources, biodiesels produced from these type of feedstocks hardly satisfies the EN14214 biodiesel standards. In this study, biomixtures were prepared by blending cottonseed biodiesel and chicken rendering fat biodiesel which were produced via transesterification method. Biodiesels were blended with each other at 60/40, 50/50 and 30/70 volume ratios to produce CO60CH40, CO50CH50 and CO30CH70 fuels. First, fuel properties of the neat biodiesels and novel biomixtures were measured and compared to European biodiesel standards and diesel. Then, the engine performance, combustion characteristics and exhaust emissions of these novel biomixture fuels were measured in a three-cylinder indirect injection diesel engine under various engine loads and at constant speed of 1500 rpm. The fuel characterisation showed that CO60CH40 and CO50CH50 biomixtures met the European standards. The Brake Specific Energy Consumption (BSEC) and Brake Thermal Efficiency (BTE) of all biomixtures were comparable with CO100, CH100 and diesel at the full engine load. The combustion results revealed that the maximum in-cylinder pressure and energy release values of the CO50CH50 were 4.2% and 4.4% higher than the diesel at full engine load because of optimised fuel properties of biomixture such as molecular structure, viscosity, cetane number and iodine value. CO50CH50 had 2.9% reduced CO 2 and comparable CO emission compared to diesel, which were also 5.6% and 13% lower than cottonseed biodiesel respectively. However, NO emission of CO50CH50 was found 3.8% and 5.8% higher than diesel and cottonseed biodiesel. A 6.5% reduction on NO emission was observed when CO60CH40 biomixture fuel was used instead of diesel. To conclude, this research showed that blending of cottonseed and chicken fat biodiesels is a promising approach to meet the EN14214 standards, improve in-cylinder pressure, optimise energy release and reduce exhaust emissions. Blending of different biodiesels will be tested as a future work

    Modified Selective Non-Catalytic Reduction System to Reduce NOx Gas Emission in Biodiesel Powered Engines

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    Biodiesel is considered as one of the attractive alternatives to fossil diesel fuel. Although biodiesels reduces most of the harmful gas emissions, they normally releases higher NOx emissions compared to fossil diesel. The Selective Catalytic Reduction (SCR) is a well-known technique used in the OEM industry to mitigate NOx emission. However, this technique may not be suitable for application in low power density engines due to back pressure and clogging issues. On the other hand, Selective Non-Catalytic Reduction (SNCR) is used in relatively large combustion operations ie. boilers and incinerators. The main disadvantage of SNCR technique is the high temperature window for diesel engine exhaust temperature. This study introduces a new design concept, which is a combination of SCR and SNCR systems, for low power density diesel engines. The developed after-treatment system composed of two main parts, injection-expansion pipe and swirl chamber. The working principle is providing maximum mixing of the injected fluid and exhaust gas in the expansion chamber, then creating a maximum turbulence in the swirl chamber. In this regard, NOx emission can be reduced at relatively lower exhaust temperatures without using any catalyst. The CFD models of three design candidates were examined in terms of velocity magnitudes, turbulence intensity and particle residence time to select the optimum physical dimensions. The selected design was manufactured and installed to exhaust system of a 1.3 litre diesel engine. Two fluids distilled water and urea-water solution were injected separately at the same flow rate of 375 ml/min. Exhaust gas emissions of fossil diesel, sheep fat biodiesel – waste cooking oil biodiesel blend and chicken fat – cottonseed biodiesel blend were tested. No significant changes in CO2 and HC emissions were observed. However, it was found that distilled water injection reduced CO and NO emissions by about 10% and 6% for fossil diesel; and by about 9% and 7% for biodiesels operation respectively. The urea-water injection led to reductions in CO and NO emissions by about 60% and 13% for fossil diesel; and by about 45% and 15% for biodiesels respectively

    Complexity aided design: The FuturICT technological innovation paradigm

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    "In the next century, planet earth will don an electronic skin. It will use the Internet as a scaffold to support and transmit its sensations. This skin is already being stitched together. It consists of millions of embedded electronic measuring devices: thermostats, pressure gauges, pollution detectors, cameras, microphones, glucose sensors, EKGs, electroencephalographs. These will probe and monitor cities and endangered species, the atmosphere, our ships, highways and fleets of trucks, our conversations, our bodies-even our dreams ....What will the earth's new skin permit us to feel? How will we use its surges of sensation? For several years-maybe for a decade-there will be no central nervous system to manage this vast signaling network. Certainly there will be no central intelligence...some qualities of self-awareness will emerge once the Net is sensually enhanced. Sensuality is only one force pushing the Net toward intelligence”. These statements are quoted by an interview by Cherry Murray, Dean of the Harvard School of Engineering and Applied Sciences and Professor of Physics. It is interesting to outline the timeliness and highly predicting power of these statements. In particular, we would like to point to the relevance of the question "What will the earth's new skin permit us to feel?” to the work we are going to discuss in this paper. There are many additional compelling questions, as for example: "How can the electronic earth's skin be made more resilient?”; "How can the earth's electronic skin be improved to better satisfy the need of our society?”;"What can the science of complex systems contribute to this endeavour?” Graphical abstrac

    ρ\rho-mass Modification in He3He^3 - a Signal of Restoration of Chiral Symmetry or Test for Nuclear Matter Models ?

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    Two recent experiments have demonstrated that the effective ρ\rho-mass in nuclear medium, as extracted from the 3He(Îł,π+π−)^3He(\gamma, \pi^+ \pi^-) reaction, is substantially reduced. This has been advocated as an indication of partial restoration of chiral symmetry in nuclear matter. We show that even in the absence of chiral symmetry, effective mean field nuclear matter models can explain these findings quantitatively.Comment: ReVTeX file with 2 postscript figures include

    ρ\rho - nucleus bound states in Walecka model

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    Possible formation of ρ\rho nucleus bound state is studied in the framework of Walecka model. The bound states are found in different nuclei ranging from 3He^3He to 208Pb^{208}Pb. These bound states may have a direct bearing on the recent experiments on the photoproduction of ρ\rho meson in the nuclear medium.Comment: RevTeX fil

    Large mass dileptons from the passage of jets through quark gluon plasma

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    We calculate the emission of large mass dileptons originating from the annihilation of quark jets passing through quark gluon plasma. Considering central collisions of heavy nuclei at SPS, RHIC and LHC energies, we find that the yield due to the jet-plasma interaction gets progressively larger as the collision energy increases. We find it to be negligible at SPS energies, of the order of the Drell-Yan contribution and much larger than the normal thermal yield at RHIC energies and up to a factor of ten larger than the Drell-Yan contribution at LHC energies. An observation of this new dilepton source would confirm the occurrence of jet-plasma interactions and of conditions suitable for jet-quenching to take place.Comment: 9 pages, 11 figures; references added, improved calculation, conclusions unchange

    Investigation of 2-butoxyethanol as biodiesel additive on fuel property and combustion characteristics of two neat biodiesels

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    Neat biodiesels are not preferred for use in the compression ignition (CI) engines due to their high viscosities and related operational difficulties. This study investigated the fuel properties and combustion characteristics when 2-butoxyethanol additive was mixed separately with waste cooking oil biodiesel (W100) and rapeseed oil biodiesel (R100). Compared to neat biodiesels, the viscosities (at 40 ⁰C) of the W100 and R100 were reduced by 12.5% and 9.8% respectively, when they were blended separately with 15% 2-butoxyethanol. Four different samples such as W100, mixture of 85% W100 and 15% 2-Butoxyethanol (W85), R100, mixture of 85 % R100 and 15% 2-Butoxyethanol (R85) were tested in a multi-cylinder CI engine. The thermal efficiency of the W85 fuel was higher than fossil diesel by approximately 3.7%. Total combustion duration of the biodiesel-additive blends were shorter than neat biodiesels and fossil diesel. Biodiesel-additive blends provided approximately 6% higher in-cylinder peak pressures. At full load, W85 fuel gave up to 5.4% reduced NOx emissions than neat biodiesel. The CO, HC and smoke emissions were decreased by up to 36%, 100% and 79% respectively. The study concluded that 2-butoxyethanol could effectively be used as biodiesel additive to improve fuel property; and to achieve better combustion and reduced pollution
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